The first command in the surface mesh creation set, this is very similar to the revolve command discussed in Chapter 9, External References and Dynamic Blocks. A curve is revolved with a given angle and around a specified axis to create the surface mesh, as we will see in this sub-section. To start the REVSURF command, you can type the command name and then press Enter, or use the short version and just type REVS and then press Enter. An alternative way is to click on the REVSURF tool button located in the Primitives panel on the Mesh tab in the 3D Modeling workspace, as shown in the following screenshot:

The REVSURF command is very similar to the revolve command. You specify the curve to be revolved, and then you specify the revolution axis and angle, as shown in the following example:

1. After starting the REVSURF command, the revolved object selection stage will end and then you will be prompted to specify the revolution axis.
2. Select an object to be used as the revolution axis (the straight line). The revolution axis selection stage will end and then you will be prompted to specify the starting and ending angles.
3. Type the starting angle and then press Enter. After that, type the ending angle and press Enter.

4. The revolved mesh surface will be created and the command terminates:

Unlike the revolve command, a surface or region cannot be used with the REVSURF command to create a solid mesh object; you can only select a line, an arc, a circle, or a 3D polyline.

The system variables, SURFTAB1 and SURFTAB2, can be used to control the density of the generated mesh. The number of divisions on the revolution direction is determined by using the SURFTAB1 variable, while SURFTAB2 controls the number of divisions in the other direction. If the revolved object is a polyline, the number specified by SURFTAB2 will be created in every straight or arc section the polyline.

Let's now have a look at the next command in the mesh surface creation set.